An electric power converter is mounted on vehicles such as a hybrid car and an electric car.
The electric power converter is for converting DC power supplied from a battery equipped in the vehicle to three-phase AC power for driving a drive motor.
As such an electric power converter is disclosed in Japanese Patent Application Laid-Open Publication No. 2013-55840, for example.
The electric power converter disclosed in the Publication '840 is provided with a plurality of semiconductor modules each with a built-in switching element, and a plurality of cooling pipes for cooling the plurality of semiconductor modules.
The plurality of semiconductor modules and the plurality of cooling pipes are stacked alternately to form a semiconductor stacked unit.
The semiconductor stacked unit is accommodated in a case together with a pressing member, and is pressed in a stacking direction thereof by the pressing member.
However, the electric power converter disclosed in the Publication '840 has the following problems.
In the electric power converter of the Publication '840, the semiconductor stacked unit is fixed in the case by the pressing force of the pressing member.
Therefore, it is necessary for the case to have rigidity to withstand the pressure of the pressing member.
Especially in a pair of walls of the case disposed in the stacking direction of the semiconductor stacked unit, since the pressure is applied intersecting perpendicularly to the pair of walls, the walls must be thickened to greatly raise the rigidity.
Thus, the weight, the cost, and the external size of the case increase, which leads to increase the weight, the cost, and the external size of the electric power converter.